D:

I have no experience dealing with US Customs concerning motorcycles, but I have dealt with them on other matters, and found them to be remarkably accomodating people, considering that they are customs officers.

I think the key advantage you have is that you can make your proposal (to exceed the normal one year limit) to them ahead of time - and generally, if you make a request to them ahead of time, you will have more options available than you have when you start to run up against a deadline.

Because you intend to store your bike, rather than ride it, the customs folks will most likely appreciate that you are not trying to evade the intent of the law, which is to limit use of foreign vehicles to 12 months. It is possible that if you propose to US Customs to put the bike into a customs bonded warehouse during the storage time, they would work with you to try and see if there is a way to meet your needs.

In other words, contact them before you import, and see what possibilities they can offer. Just don't ask them when you drive up to the border about this, otherwise, they will be forced to cause you grief, because you will have indicated to them that you intend to stay longer than you should. They then won't be able to let you in until a solution is reached (and this might involve posting a bond).

Try their website: U.S. Customs Service